IndyCar medical director Dr. Michael Olinger said James Hinchcliffe is "progressing well," but the Andretti Autosport driver hasn't been cleared to return after sustaining a concussion.

Hinchcliffe, who was injured after his helmet was struck by debris during Saturday's inaugural Grand Prix of Indianapolis, was evaluated Tuesday by the IndyCar medical team in conjunction with its neurosurgical consultant. Olinger said Hinchcliffe had been cleared to begin light training.

Hinchcliffe will be re-evaluated Thursday. IndyCar typically makes IndyCar drivers with concussions wait a minimum of seven days before being cleared. But the series said in a Sunday statement that concussions are handled on a case-by-case basis, and that drivers with head injuries must pass an ImPACT test before being cleared by Olinger.

Indianapolis Motor Speedway is open daily for Indianapolis 500 practice this week. Pole qualifying for the Indy 500 is Saturday. The final day of qualifying is Sunday.

Andretti has been using EJ Viso as a substitute in Hinchcliffe's No. 27. Dallara-Honda. During a rain-shortened practice Tuesday, Viso posted the fastest speed (224.488 mph), just ahead of Kurt Busch (224.159).

"I've taken on the full role of (Hinchcliffe)," Viso said. "Whatever his crew and engineer had planned to test and experience, I've been doing.

"It has been a quick adaptation to the team for me and so far it's all been pretty positive. My biggest wish is to Hinch and to his recovery. Hopefully, he's going to be able to make it to the race."